Lens mount for photographic cameras



Jan. 6, 1942. STEWER 2,269,401

LENS MOUNT FOR PHOTOGRAPHIC CAMERAS Original Filgd Jan. 12, 1940 3 Sheets-Sheet l 'lOJ io m

121210921202".- Oscar Sie 2/2202",

6 gay; MM

12, 1940 3 Sheets-Sheet 2 MPma , it: t:

Imvenior:

Jan. 6, 1942. 0. STEINER I LENS MOUNT FOR PHOTOGRAPHIC CAMERAS Original Filed Jan.

WNW) UH Jan. 6, 1942. o. STEINER LENS MOUNT FOR PHOTOGRAPHIC CAMERAS Original Filed Jan. 12, 1940 SSheets-Sheet 3 Invenifo 2". 060a? d'ieznez Patented Jan. 6, 1942 I UNITED STATES PATENT OFFlCE LENS MOUNT roa rnorocasrmo camaaas Oscar Steiner, Irondequoit, N. Y., assignor to The FolmerGraflex Corporation, Rochester, N. Y., a corporation of Delaware Original application January 12, 1940, Serial No. 313,534, now Patent No. 2,236,925, dated April 1, 1941. Divided and this application February.4, 1941, Serial No. 377,317

. a Claims. (01. 95-64) Fig. 2 is a side elevation of Fig. 1;

Fig. 3 is a vertical section through the lens mount, showingthe relation of the illustrated parts;

Fig. 4 is a vertical section through the lens mount, showing the automatic diaphragm resilient bumper and means connecting the diaphragm ring latch dog; I

Fig. 5 is a sectional detail on the line 5-4 of i Fig. 6 is a sectional detail on the line 9-6 of Figs. 7 and 8;

Fig. -7 is a view similar to Fig. 1 excepting that certain parts appear in section, so as more clearly to show the construction of the diaphragm operating means;

Fig. 8 is a view similar to Fig 'l, but on a smaller scale, and showing the connection between the automatic diaphragm adjusting ring and the automatic diaphragm operating pawl;

Fig. 9 is a side elevation of one of the diaphragm leaves to show more clearly the position of the diaphzagm leaf operating pins; and

Fig. 10 is a top plan view of Fig. 9.

It is well known to the users of single-lens a lens having the automatic diaphragm mechareflex cameras that it would be a decided advantage to focus with the diaphragm wide open,

1 thereby having available a greater quantity of sirous of making an exposure atjzll, as a rule,

insufficient light would reach the ground glass focusing screen to focus the camera accurately.

However, if the diaphragm were open, sayto i345, adequate light would be .had. But in making these changes manually, the operator often forgets or does not have the time to adjust the diaphragm to its-proper setting after focusing.

I herein disclose automatic means for doing this,

lens is set at the full open position and a preselected stop is chosen and adjustment made ac- .cordingly. At the instant of making the exposure, the diaphragm operating mechanism is released automatically, closing down the diaphragm to that pre-selected opening without any thought on the part of the operator.

There have. been several attempts to provide means for accomplishing this result. -The mechanism disclosed in the patent to Terkel Korling No. 2,029,238, dated January 28, 1936, is so far as I am aware the nearest approach in the prior art to a satisfactory solution of this problem.

To have a satisfactorily operating automatic diaphragm stop, it is necessary that it work not only on one particular lens but on any lens that may be chosen to be used with the camera, and it the present disclosure this is taken care of, and

any lens, if provided with automatic diaphragm adjusting means, is, in the practice of my invention, instantly coupled with the operating mechanism when that lens is inserted in the camera.

Preferably lenses and lens boards can readily be changed without in any way making adjustments of or in the diaphragm control means. The disclosure in the said Korling patent is confined to the use of one lens only, whereas in accordance with the present disclosure any number of lenses can be used interchangeably, provided the lens mounts are equipped with the automatic feature, and th can all be controlled from the mirror-release echanism.

I will now describe the lens barrel with the automatic diaphragm built thereinto and for that purpose I will refer first and more particularly to Figs. 1 to 6 inclusive.

In Fig. 1 there is shown a diaphragm scale 9.0 which is held to the flange 39 of the lens board 32 by screws a, 99a. The said scale is provided with markings indicated generally at 9| and with index holes indicated generally at 92 as placed in alignment with the markings 9|. A diaphragm stop adjusting handle is represented at 93, a diaphragm ring-setting knob at 94 and a diaphragm-retaining dog at I22. The mounting of the lens cells 98 and. 9'1 upon the lens barrel 98 is shown in Fig. 2.

In Fig. 3, the lens barrel structure, indicated generally at 98, is shown in transverse section,

and in Fig. 4-the diaphragm stop-setting or adjusting ring is indicated at 99, the diaphragm or member II! will actuating .ring I04 and diaphragm leaves I05, 5 each of which is provided with a pin I06 and a pin I01, best shown in Figs, 9 and 10.

The stationary diaphragm ring I03 is fastened to the lens barrel 08 in any suitable or usual manner. as by means of plus. The diaphragm 10 actuating ring I04 is free to turn sufllciently far to cause the diaphragm aperture to be closed or stopped'down to the smallest aperture. As shown in Fig. 4, the lens barrel 98 is provided with a slot Ill, and riding in the said slot I" is a diaphragm dog-plate lormember I09 attached to the diaphragmactuating ring I04 and the diaphragm ring III by means of screws H0, H0. The diaphragm stop-setting and adjusting ring 90 has a v radially member III to which the adlusting handle or knob II. is attached. The diaphragin stop-setting or adjusting ring 90 is provided with a notched-out p rtion or slot Ii! to aii'ord clearance for the diaphragm dog-plate adjusting i 00 is'provided with a coiled spring II! a pin III of the diaphragm dogplate Ill. The purpose thereof'isto absorb the a jar when the diaphragm-achiating ring I04 and the diaphragm ring I00 are stopped against the end of the notched-out portion or slot II! of the diaphragm stop-setting or adjusting ring 00.

' The diaphragm. return-spring cover I0! is provided with an ning in which the spring IN is positioned asshowninFigs. 8,5and6. Oneend .15

of the said spring in is attached to the lens barrel ll bymeana'of a screw III, shown in Fig. 7, and the opposite end of-said spring IOI is attached to the diaphragm dog-plate or member 7 III by means of a pin I", also shown in Fig. "I, 40

being wrapped about the lens barrel 00 a number of times, three turns being indicated in Fig. 5.

The said spring III has sumcient tension to return the dia hragm dog-plate or member I 0! to a position wherein one contact with the end of the notch or slot '2 of the diaphragm stopsetting: or adjusting ring 00. saidediaphragm stop-setting or adjusting ring 09 is adjustable between the hole 02 opposite the diaphragm member 1:32, and the hole 02 opposite the dia--' phragm [:4 aslimits. It will therefore be seen that the position of the end of the notch or slot III willbe varied between these two extremes.

The structure of parts just set forth makes possible the use of a flat type coiled spring, such as III, which is of the type known as a "clock spring, being rectangular in cross section and of substantial width. Such spring has a nearly uniform tension within the operating limits, as is so highly desirable in this invention. The said type of spring, becauseof its uniform torque or tension, provides a smoother operating diaphragm, operating under very much lower spring occur it'- the regular type of helical spring were used. when such usual helical spring is Qinployed to operate the diaphragm, the initial tension required is so great that the inertia set up edge of said plate 45 These leaves are usually made up of very thinsteel, never over .003. On either end of each or these leaves is provided a pin I01 (Figs. 9-and 10) which pins necessarily have to be riveted to such leaves. Since these'leaves are of such thin material, it is impossible to get a satisfactory structure as far as strength is concerned. For a helical type of spring, such as heretofore usedin diaphragm operating mechanism, to have sufilcient powerover the full range of movement, it w ,hadtobe tensioned or stretched to a point where its tension'was very high at the moment of re- 1 "leasing the diaphragm. This set the diaphragm thus making the diaphragm inoperative and useless. In addition to the advantages secured by. the use of the spring IN, the coiled spring II3 I and the pin III provide means for absorbing part III. One end of the diaphragm stop-setting or 5 diaphragm ring, said coiled spring II3 being of the inertia set up in the movement of the caused to be compressed by pin Ill at the end of the travel of the diaphragm ring clockwise, viewin'g Fig. 4. Such. inertia-absorbing means, if the usual helical spring were used, would not be sufilcient to prevent the rapid destruction of the diaphragm leaves, but when used in cooperation with the ilat spring III they are entirely suf- -iicient for the purpose. 4

' As shown in Fig. 5, the diaphragm stop-ad-' justing knob or handle 93 is provided with a pin III having a shoulder I I0 and a dowel end II! for engaging any of the holes 02 inthe plate 90.

The pin II'I'is caused to be thfustdownward under the influence of a spring I20 in the barrel I2I, as shown in Fig.5. The said barrel I2I is threaded into the radially extending'member II I, of the diaphragm stop-setting or adjusting ring 00. In Fig. 4, the diaphragm actuatingring I08 a bearing 82. Inasmuch as said dog-plate ,or

n'1ember'l09 is attached to the diaphragm actuat ing .ring I04, the said ring will also be turned in a -contraclockwise direction suihciently far to open completely the diaphragm, and the said ring I04 will be held in this position until released in a manner already described. This op- Inasmuch-as the diaphragm stop-setting or adjusting eration puts tension on the spring IOI.

ring 09 can be adjusted to any position within the limits of f:32 or ,fi4, or any other diaphragm setting that is or may be provided, the said dia- 'ph-ragm dog plate or member I09 will be stopped against'the end of the. notch or slot II2 when the dog-I22 is released from the diaphragm-re- I lease catch 84. tension, thus preventing the usual jar that would 05 It will 'be understood from the just preceding description of parts that I have provided means for suflicientl'y opening the diaphragm and holding it in open position and then allowing it to be stopped down to any pre-selected condition upon in the moving parts is suihcient to cause rapid the release of the diaphragm release catch.

diaphragm leaf of aconventional lens mount; 7

.The action of the diaphragm leaves I05 is accomplished in a manner already referred to and well known in the art; that is to say, as best shown in Figs. 9 and 10, each leaf I05 isprovided with the two pins I06, I0I at opposite ends and faces thereof. The pins I06 engage holes in the stationary diaphragm ring I03 and the pins I01 engage slots I23 in the diaphragm ac- I tuating ring I04, as shown in Figs. 1, 3, 4, 7 and 8.

As the diaphragm actuating ring I04 is turned either in a clockwise or contraclockwise direction, the'diaphragm leaves I05 will be moved. If said diaphragm actuating ring I04 is moved in-a contraclockwise direction, the diaphragm leaves I05 will be caused to open up, thus providing a full aperture, and when said diaphragm actuating ring I04 is turned in a clockwise. direction, the said diaphragm leaves I 05 will be caused to close up more or less, as shown, for example, inFigs. 1, 7 and 8, thus providing any aperture previously selected.

Having thus described one illustrative embodi- I ment of the invention, it is to be understood that although specific terms are employed, they are used in a generic and descriptive sense and not for purposes of limitation, the scope of the invention being set forth in the following claims.

I claim:

1. A lens mount for photographic cameras and like purposes, including, incombination, a lens barrel, .a diaphragm ringhaving diaphragm means, a diaphragm, stop-setting, justing ring, and a diaphragm actuating ring free to be turned to stop down the lens aperture, said rings all being concentric with the lens barrel, and a long, thin, metal, diaphragm-return spring IIII having one end thereof connected to said lens barrel diaphragm actuating ring, said spring being wrapped in a spiral. a plurality 0! turns in the same transverse path about said lens barrel, said spring being or greatly elongated rectangular form in cross section, and thus being of prolonged width compared with its thickness, the said spring, because of its said structure and end con-- nections, imparting a substantially equal force to said diaphragm actuating ring throughout the movement of the latter, thus providing substantially the same amount of tension at the end of its travel as at its start thereof, and permitting a lower over-all spring tension for the operation of the diaphragm ring.

2. A combination according to claim 1 wherein the diaphragm actuating ring has attached thereto a diaphragm dog-plate having a dog adapted to be engaged by a diaphragm return catch, the said diaphragm return spring IOI beof said dog-plate impacting in its movement against said jar-absorbing spring. 5. A combination according to claim 1, in which the diaphragm stop-setting, adjusting ring is -a segmental, open ring provided at one end with and the opposite end thereof connected to said a jar-absorbing coil spring III, and in which the said diaphragm actuating ring has a segmental diaphragm dog-plate attached thereto and provided with a projecting pin II4 to engage said coil spring Ill.

, 'OSCAR STEINER. 

